Testing of Semi–Strong Form of Efficiency: an Empirical Study on Stock Market Reaction Around Dividend Announcement

Purpose: The purpose of this study is to examine the efficiency of the Indian stock market of the Nifty IT index over the dividend announcement for five years from 2016 to 2020.   Theoretical framework: A reward procured by the shareholders on their equities is, of course, the dividend. A leading area of concern is the dividend announcement. According to the theory of efficient markets, stock prices accurately reflect all available information. This demonstrates that the prices are correct and fair. The market should therefore respond immediately to an event in this instance the dividend announcement. Therefore, depending on publicly available information will not provide investors with the possibility to consistently generate extraordinary returns.   Design/ methodology/ approach: The study attempts to validate the event study approach while investigating the semi-strong form of efficiency. Daily share prices of five companies out of ten of the Nifty IT index were observed to test the Efficient Market Hypothesis. 31 days event window has been employed to calculate the abnormal returns of the selected sample around dividend issue announcements also t-test was applied to assess the level of significance.   Findings: The study found that the stock market was efficient in its semi strong form and the investors could not make excess returns over the dividend announcement of the Nifty IT index.   Research, Practical & social implications: This study eliminates the possibility for investors to beat the average market returns. It is significant since it affects stock market investment choices.   Originality/ Values: The majority of studies are only able to analyse the overall average abnormal return and cumulative average abnormal return of chosen companies; it is difficult to locate studies that focus on the abnormal return for each individual company. The t test for each company-wise abnormal returns, overall average abnormal returns, and cumulative average abnormal returns were acquired and tested at the 5% level of significance in order to determine the significance.

Time resolved area normalized emission spectroscopy (TRANES) of DMABN confirms emission from two states

4-N, N-Dimethylaminobenzonitrile (DMABN) is a simple molecule which is extensively studied to understand the excited state kinetics and the origin of time dependent fluorescence in several organic solvents. We use a recently described method, time resolved area normalized emission spectroscopy (TRANES), for the analysis of wavelength dependent fluorescence of DMABN in acetonitrile and 1,4-dioxane. An isoemissive point was observed in the TRANES spectra, which confirms that there are only two emissive species A∗ and B∗:A→A∗⇔B∗

TRANES analysis of the fluorescence of nile red in organized molecular assemblies confirms emission from two species

Time-resolved area normalized emission spectroscopy (TRANES) is a new method for the analysis of fluorescence of dyes in complex chemical and biological systems (A S R Koti, M M G Krishna and N Periasamy, 2001,J. Phys. Chem. 105, 1767). The model-free method extends the power of time-resolved emission spectroscopy (TRES) analysis and removes the ambiguity in the interpretation when the emission spectrum is time-dependent. Observation of an isoemissive point in TRANES analysis of fluorescence is an unambiguous indication for the presence of two emissive species in the sample. The isoemissive point occurs at a wavelength where the ratio of the radiative rates of the two species is equal to the ratio of their total radiative rates. The polarity-sensitive nile red dye shows time-dependent emission spectra in the organized bilayer assemblies of TX micelle and bilayer egg-phosphotidylcholine (egg-PC) membrane. Time-dependent spectra in complex systems support many important models (solvation model and heterogeneity in the ground and/or excited state). TRANES analysis shows that the fluorescence emission of nile red in TX micelle and egg-PC membrane is due to two emissive species solubilized in different sites

Solvent exchange in excited-state relaxation in mixed solvents

The fluorescence of styrylthiazoloquinoxaline (STQ) in the solvent mixture methanol and dichloromethane (DCM) and 2-octanol have many common characteristics: biexponential fluorescence decay, wavelength-dependent amplitudes, a negative amplitude for the short-lifetime component at long emission wavelengths, and a time-dependent red shift of the emission spectrum. In octanol, the fluorescence lifetime decreases with increasing temperature, whereas the lifetime increases with temperature in the methanol/DCM mixture. The fluorescence characteristics in 2-octanol (η=7.29 cP) are readily explained by the conventional model of excited-state relaxation kinetics by solvent reorientation. This model is not applicable for low-viscosity (η=0.455 cP) solvent mixtures. A model of excited-state relaxation kinetics involving solvent exchange (versus solvent reorientation in pure solvents) in the excited state is proposed for the solvent mixture. The model assumes that the solvent compositions around the solute are different in the ground and excited states and the solvent composition is temperature dependent

Synthesis, photoluminescence and electrochemical properties of 2,7-diarylfluorene derivatives

A new class of highly fluorescent 9,9'-bis-(alkyl)-2,7-diarylfluorene having electron withdrawing or electron donating groups on the p-phenyl positions were synthesized and characterized. The highly luminescent fluorene derivatives, 1-6 showed blue emission (376-416 nm), narrow FWHM (~50 nm), high quantum yield (ΦF=0·12-0·87) and short fluorescence lifetimes, τF=0·23-1·14 ns. The HOMO levels of 9,9'-bis-(alkyl)-fluorene were tuned by the ρ-substituents at 2,7-phenyl group. Hammett correlation with EHOMO of these new molecules provides an effective tool to predict the HOMO level of similar molecules prior to the synthesis. These data indicate that they are useful as emitting materials for organic light emitting devices, OLEDs

Synthesis, photophysical and electrochemical properties of 2,8-diaryl-dibenzothiophene derivatives for organic electronics

A series of 2,8-p-diaryldibenzothiophene derivatives were synthesized and characterized. These molecules have electron withdrawing or electron donating groups at the para phenyl position, which alters the electronic properties of these derivatives. The quantum yield, fluorescence lifetime, singlet, triplet and EHOMO energy levels of these compounds were determined by fluorescence, phosphorescence and cyclic voltammetry. A plot of Hammett constants of the para substituents vs EHOMO revealed a linear relationship. The usefulness of these molecules in organic light emitting diodes, OLEDs is discussed vis-à-vis the energy levels and properties

Translational diffusion of fluorescent probes on a sphere: monte carlo simulations, theory, and fluorescence anisotropy experiment

Translational diffusion of fluorescent molecules on curved surfaces (micelles, vesicles, and proteins) depolarizes the fluorescence. A Monte Carlo simulation method was developed to obtain the fluorescence anisotropy decays for the general case of molecular dipoles tilted at an angle a to the surface normal. The method is used to obtain fluorescence anisotropy decay due to diffusion of tilted dipoles on a spherical surface, which matched well with the exact solution for the sphere. The anisotropy decay is a single exponential for α = 0° , a double exponential for α = 90° , and three exponentials for intermediate angles. The slower decay component(s) for α ≠ 0 arise due to the geometric phase factor. Although the anisotropy decay equation contains three exponentials, there are only two parameters, namely a and the rate constant, Dtr/R2, where Dtr is the translational diffusion coefficient and R is the radius of the sphere. It is therefore possible to determine the orientation angle and translational diffusion coefficient from the experimental fluorescence anisotropy data. This method was applied in interpreting the fluorescence anisotropy decay of Nile red in SDS micelles. It is necessary, however, to include two other independent mechanisms of fluorescence depolarization for molecules intercalated in micelles. These are the wobbling dynamics of the molecule about the molecular long axis, and the rotation of the spherical micelle as a whole. The fitting of the fluorescence anisotropy decay to the full equation gave the tilt angle of the molecular dipoles to be 1± 2° and the translational diffusion coefficient to be 1.3± 0.1×10-10 m2/s

Bimodality and hysteresis in systems driven by confined L\'evy flights

We demonstrate occurrence of bimodality and dynamical hysteresis in a system describing an overdamped quartic oscillator perturbed by additive white and asymmetric L\'evy noise. Investigated estimators of the stationary probability density profiles display not only a turnover from unimodal to bimodal character but also a change in a relative stability of stationary states that depends on the asymmetry parameter of the underlying noise term. When varying the asymmetry parameter cyclically, the system exhibits a hysteresis in the occupation of a chosen stationary state.Comment: 4 pages, 5 figures, 30 reference

Photoconduction in Alq3

Photoelectronic properties of Alq3 were studied by photoconductivity measurements in thin film, sandwich (ITO/Alq3/LiF/Al) devices. We find that the photocurrent is dominated by bulk generation of carriers for incident photon energies greater than 2.75 eV. The quantum efficiency of photocarrier generation has been measured from carrier collection measurements to be about 10%. The quantum efficiency is largely independent of electric field. This enables a direct measurement of the electric field dependence of mobility using photoconductivity measurements, which is used for quantitative analysis of the dark forward current in these devices. Photoconductivity measurements were also used to obtain (\mu_{0n} \tau_n) product which can be used as a measure of material quality. For Alq3, we find that the value of (\mu_{0n} \tau_n) product was between 3x10^{-15} cm^2/V to 8x10^{-15} cm^2/V for different samples. In forward bias, at high field the photocurrent shows saturation accompanied by a phase shift. These effects are attributed to space charge effects in the device.Comment: 12 figure